Dataset Information

Heterogeneities in Leishmania infantum infection: using skin parasite burdens to identify highly infectious dogs.

ABSTRACT:

Background

The relationships between heterogeneities in host infection and infectiousness (transmission to arthropod vectors) can provide important insights for disease management. Here, we quantify heterogeneities in Leishmania infantum parasite numbers in reservoir and non-reservoir host populations, and relate this to their infectiousness during natural infection. Tissue parasite number was evaluated as a potential surrogate marker of host transmission potential.

Methods

Parasite numbers were measured by qPCR in bone marrow and ear skin biopsies of 82 dogs and 34 crab-eating foxes collected during a longitudinal study in Amazon Brazil, for which previous data was available on infectiousness (by xenodiagnosis) and severity of infection.

Results

Parasite numbers were highly aggregated both between samples and between individuals. In dogs, total parasite abundance and relative numbers in ear skin compared to bone marrow increased with the duration and severity of infection. Infectiousness to the sandfly vector was associated with high parasite numbers; parasite number in skin was the best predictor of being infectious. Crab-eating foxes, which typically present asymptomatic infection and are non-infectious, had parasite numbers comparable to those of non-infectious dogs.

Conclusions

Skin parasite number provides an indirect marker of infectiousness, and could allow targeted control particularly of highly infectious dogs.

SUBMITTER: Courtenay O

PROVIDER: S-EPMC3886905 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature

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Publications

Heterogeneities in Leishmania infantum infection: using skin parasite burdens to identify highly infectious dogs.

Courtenay Orin O Carson Connor C Calvo-Bado Leo L Garcez Lourdes M LM Quinnell Rupert J RJ

PLoS neglected tropical diseases 20140109 1

<h4>Background</h4>The relationships between heterogeneities in host infection and infectiousness (transmission to arthropod vectors) can provide important insights for disease management. Here, we quantify heterogeneities in Leishmania infantum parasite numbers in reservoir and non-reservoir host populations, and relate this to their infectiousness during natural infection. Tissue parasite number was evaluated as a potential surrogate marker of host transmission potential.<h4>Methods</h4>Parasi ...[more]

PMID: 24416460

Similar Datasets

Project description:BACKGROUND:Leishmaniasis is a vector-borne neglected disease. Inside the natural sand fly vector, the promastigote forms of Leishmania undergo a series of extracellular developmental stages to reach the infectious stage, the metacyclic promastigote. There is limited information regarding the expression profile of L. infantum developmental stages inside the sand fly vector, and molecular markers that can distinguish the different parasite stages are lacking. METHODOLOGY/PRINCIPAL FINDINGS:We performed RNAseq on unaltered midguts of the sand fly Lutzomyia longipalpis after infection with L. infantum parasites. RNAseq was carried out at various time points throughout parasite development. Principal component analysis separated the transcripts corresponding to the different Leishmania promastigote stages, the procyclic, nectomonad, leptomonad and metacyclics. Importantly, there were a significant number of differentially expressed genes when comparing the sequential development of the various Leishmania stages in the sand fly. There were 836 differentially expressed (DE) genes between procyclic and long nectomonad promastigotes; 113 DE genes between nectomonad and leptomonad promastigotes; and 302 DE genes between leptomonad and metacyclic promastigotes. Most of the DE genes do not overlap across stages, highlighting the uniqueness of each Leishmania stage. Furthermore, the different stages of Leishmania parasites exhibited specific transcriptional enrichment across chromosomes. Using the transcriptional signatures exhibited by distinct Leishmania stages during their development in the sand fly midgut, we determined the genes predominantly enriched in each stage, identifying multiple potential stage-specific markers for L. infantum. CONCLUSIONS:Overall, these findings demonstrate the transcriptional plasticity of the Leishmania parasite inside the sand fly vector and provide a repertoire of potential stage-specific markers for further development as molecular tools for epidemiological studies.

Project description:BackgroundThree species of Leishmania cause disease in humans in Israel and are endemic in the Middle East: Leishmania infantum, Leishmania tropica and Leishmania major. These species infect dogs and cats, but little is known about their prevalence in pet populations and their clinical manifestations. A study on dog and cat Leishmania infection was conducted in a focus of human L. tropica infection in central Israel with the aim of getting insight on leishmaniosis in pets in an area where human infection is highly prevalent.MethodsBlood, demographic and clinical data were collected from dogs and cats brought for veterinary care in a focus of human L. tropica infection during 2018-2020. kDNA PCR and internal transcribed spacer1 high-resolution melt analysis PCR (ITS1 HRM PCR) with DNA sequencing were performed for the detection of Leishmania and species determination.ResultsForty-three of 189 dogs (22.8%) and 44 of 152 cats (28.9%) were positive for Leishmania spp. infection by kDNA PCR. The ITS1 HRM PCR detected six dogs (3.3%) infected with L. infantum and one (0.5%) with L. tropica, whereas six cats (3.9%) were found infected by L. infantum and five (3.3%) by L. tropica. Four of the five L. tropica-positive cats suffered from weight loss, four had azotemia, two with mild and two with severe azotemia and progressive renal disease. Three cats had gingivostomatitis; three had skin lesions with abscess and ulcers in two and scales and hair loss in another cat, which was also FIV +. This is the first report of feline L. tropica infection in Israel. Clinical information on cats with this infection from previous studies elsewhere is scarce.ConclusionsA high rate of Leishmania spp. infection, mostly estimated as sub-clinical, was found in dogs and cats admitted for veterinary care in an L. tropica focus. Among the animals in which infection could be characterized to the species level, more dogs were infected with L. infantum than with L. tropica while 5 of 11 cats were infected with L. tropica and had signs of systemic and skin disease not described before in feline L. tropica infection.

Dataset Information

Heterogeneities in Leishmania infantum infection: using skin parasite burdens to identify highly infectious dogs.

Background

Methods

Results

Conclusions

Publications

Heterogeneities in Leishmania infantum infection: using skin parasite burdens to identify highly infectious dogs.

Similar Datasets

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